The invention concerns a method for disinfecting a microtome cryostat, comprising a defrosting phase, provision of a vaporous disinfectant which acts upon the closed cryostat chamber, and a period of time during which the disinfectant is effective. An associated device for disinfecting a microtome cryostat, comprises a microtome in a cryostat chamber, a refrigerator, a means for providing a vaporous disinfectant, and a disinfectant controller means to set an effective time after a defrosting phase.
Disinfection is necessary to protect the operating personnel since microtomes are used for cutting tissue samples which are often infected with germs. Spraying is problematic, in particular, for cryostat microtomes, since the moisture must be removed from the cryostat chamber. Residual moisture on a cryostat microtome freezes after refrigeration for the next working step. Guidances etc. may thereby freeze with the consequence that the microtome is inoperable, or liquid disinfectant, e.g. a highly concentrated alcohol solution, remains in the chamber and causes further problems, even danger of explosion.
US 2002/0139124 A1 proposes a solution to this problem by disinfection with ozone. This is, however, disadvantageous, since ozone is highly corrosive and damages the surfaces via oxidation. A further disadvantage is that residual ozone is difficult to remove, is poisonous and highly inflammable, and can partially escape from the device even during the disinfecting phase, which could endanger the operating personnel.
The company leaflet “AS 600 Cryotome” (ANGLIA SCIENTIFIC) proposes another solution for decontamination using UV radiation. Disadvantageously, the UV radiation does not reach the shadow regions. Moreover, the UV radiation cannot penetrate deeply enough into cutting waste or sample residues nor into microscopically small depressions in metal surfaces. This method of decontamination is therefore unsatisfactory.
A proposal of the above-mentioned type is disclosed in the company leaflets “AS 620 Cryotome” and “AS 620 Cryotome Instruction Manual” (ANGLIA SCIENTIFIC Instruments LTD). A formalin dispenser is thereby heated and the closed cryostat chamber is charged with formalin vapor. The above-mentioned problem of residual moisture in the cryostat and, in particular, on the microtome, also occurs in this case with the consequence that the device must be left open for a relatively long time to dry. Disinfectant thereby escapes which should be prevented for health reasons and due to possible annoyance caused by bad smell. Moreover, the device is inoperable for a relatively long time or is not completely dried.
It is therefore the underlying purpose of the invention to further develop a method and associated device of the above-mentioned type to ensure rapid and effective disinfection to permit as fast a renewed operation of a microtome cryostat as possible as well as complete drying thereof.